Compound suitable for use as a catalyst or for producing a catalyst system derived from a bis-phosphorinane

ABSTRACT

The invention relates to a compound of formula (I) wherein X represents a low alkylen group, an arylene group or an alkarylene group, L1 has formula (II) wherein Y1 represents oxygen, sulphur or N—R17, R11, R12, R13, R14, R15, R16, R17 independently represent hydrogen, alkyl or aryl, L2 has formula (III) wherein Y2 represents oxygen, sulphur or N—R27, R21, R22, R23, R24, R25, R26, R27 independently represent hydrogen, alkyl or aryl wherein L1 and L2 can be identical or different. The inventive compound is suitable for use as a catalyst or for producing a catalyst system.

[0001] The present invention relates to a compound of formula (I)suitable as a catalyst or for the preparation of a catalyst system:

L¹-X-L²   (I)

[0002] in which

[0003] X is a lower alkylene group, an arylene group or an alkarylenegroup;

[0004] L¹ is

[0005] in which

[0006] Y¹ is oxygen, sulfur or N—R¹⁷,

[0007] R¹¹, R¹², R¹³, R¹⁴, R¹⁵, R¹⁶ and R¹⁷ independently of one anotherbeing hydrogen, alkyl or aryl; and

[0008] L² is

[0009] in which

[0010] Y² is oxygen, sulfur or N—R²⁷,

[0011] R²¹, R²², R²³, R²⁴, R²⁵, R²⁶ and R²⁷ independently of one anotherbeing hydrogen, alkyl or aryl,

[0012] it being possible for L¹ and L² to be identical or different.

[0013] It further relates to a process for the preparation of a compoundof formula (I), to the use of a compound of formula (I), to systems (VI)suitable as catalysts and obtainable by reaction with a compound offormula (I), and to processes for the carbonylation of olefinicallyunsaturated compounds in the presence of a compound of formula (I) or asystem of formula (VI).

[0014] Processes for the catalytic carbonylation of olefinicallyunsaturated compounds, i.e. for their reaction with carbon monoxide anda compound containing a hydroxyl group, in the presence of a catalyst,to give an acid or derivatives thereof, are generally known.

[0015] Thus, for example, the carbonylation of n-pentenoic acid orderivatives thereof of formula (XII) can give adipic acid or derivativesthereof, which are extensively used in the manufacture of industriallyimportant polymers, especially polyamides.

[0016] Processes for the carbonylation of n-pentenoic acid orderivatives thereof of formula (I) are disclosed for example inGB-1497046, DE-A-2541640, U.S. Pat. No. 4,508,660, EP-A-373579, U.S.Pat. No. 4,933,483, EP-A-450577, U.S. Pat. No. 4,257,973, WO 2000/14055,EP-A-577204, WO 2000/56695, EP-A-662467 or WO 2000/42717.

[0017] The carbonylation of olefinically unsaturated compounds (exceptfor ethylene) normally gives linear and branched products.

[0018] In the case of the carbonylation of n-pentenoic acid, only thelinear products are used extensively, while the branched products are ofno importance or are only of secondary importance as far as quantity isconcerned.

[0019] What is desirable, therefore, is a high n/i ratio coupled with ahigh yield. The n/i ratio is understood as meaning the ratio of theselectivity in respect of linear products to the selectivity in respectof branched products. The term linearity used in this connection in thestate of the art denotes the selectivity in respect of linear products.The n/i ratio is calculated from the linearity according to the equation

n/i ratio=linearity [%]/(100%−linearity [%])

[0020] The n/i ratio coupled with a high yield is unsatisfactory in saidprocesses.

[0021] Thus, in Example 6 of U.S. Pat. No. 4,933,483, an n/i ratio of 24(linearity 96%) is achieved for a yield of only 70%.

[0022] WO 98/42717, Example 7, discloses a yield of 84% (conversion100%, selectivity 84%); however, the n/i ratio is only 5.25 (84% oflinear product, the remainder being 16% of branched product).

[0023] It is an object of the present invention to provide a compoundsuitable as a catalyst or for the preparation of a system suitable as acatalyst, which compound avoids said disadvantages in a technicallysimple and economic manner.

[0024] We have found that this object is achieved by the compound offormula (I) defined at the outset, by a process for the preparation of acompound of formula (I), by the use of a compound of formula (I), bysystems (VI) suitable as catalysts and obtainable by reaction with acompound of formula (I), and by processes for the carbonylation ofolefinically unsaturated compounds in the presence of a compound offormula (I) or a system of formula (VI).

[0025] According to the invention, the compound of formula (I) has thestructure

L¹-X-L²   (I).

[0026] Possible meanings of X are a lower alkylene group preferablyhaving from 1 to 6 and especially from 1 to 4 carbon atoms between thetwo radicals L¹ and L², particularly preferably methylene, 1,2-ethylene,1,3-propylene or 1,4-butylene, an arylene group, preferably1,2-phenylene, 1,3-phenylene or 1,4-phenylene, or an alkarylene group,preferably 1,2-benzylidene, 1,3-benzylidene, 1,4-benzylidene,1,2-xylylidene, 1,3-xylylidene or 1,4-xylylidene.

[0027] In one preferred embodiment, it is possible to use a loweralkylene group preferably having from 1 to 6 and especially from 1 to 4carbon atoms between the two radicals L¹ and L², particularly preferablymethylene, 1,2-ethylene, 1,3-propylene or 1,4-butylene.

[0028] The arylene group, alkylene group or alkarylene group can carrysubstituents such as alkyl groups, for example methyl, ethyl, n-propyl,i-propyl, n-butyl, i-butyl, s-butyl or t-butyl, aryl groups, for examplephenyl or p-tolyl, halogens, for example fluorine, chlorine or bromine,alkoxy and aryloxy, but it preferably carries no substituents.

[0029] One or more carbon atoms in the arylene group, alkylene group oralkarylene group can be replaced with heteroatoms such as nitrogen,oxygen, sulfur or silicon, it being possible for the heteroatom(s),independently of one another and independently of the remainingstructure of X, and according to the particular valency, to carrysubstituents such as hydrogen, alkyl groups, for example methyl, ethyl,n-propyl, i-propyl, n-butyl, i-butyl, s-butyl or t-butyl, aryl groups,for example phenyl or p-tolyl, halogens, for example fluorine, chlorineor bromine, alkoxy and aryloxy. Preferably, carbon in the arylene group,alkylene group or alkarylene group is not replaced with heteroatoms.

[0030] A possible meaning of L¹ is a structure of the formula

[0031] In this formula, Y¹ is oxygen, sulfur or N—R¹⁷, preferablyoxygen. Possible groups R¹¹, R¹², R¹³, R¹⁴, R¹⁵, R¹⁶ and R¹⁷independently of one another are hydrogen, alkyl, preferably alkylhaving from one to 6 and especially from one to 4 carbon atoms, or arylsuch as phenyl or p-tolyl.

[0032] In one preferred embodiment, the groups R¹¹, R¹², R¹³, R¹⁴, R¹⁵,R¹⁶ and R¹⁷ used can independently of one another be a radical selectedfrom the group comprising hydrogen, methyl, ethyl, n-propyl, i-propyl,n-butyl, i-butyl, s-butyl and t-butyl.

[0033] The groups R¹¹, R¹², R¹³, R¹⁴, R¹⁵, R¹⁶ and R¹⁷ can independentlyof one another carry substituents such as alkyl groups, for examplemethyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, s-butyl or t-butyl,aryl groups, for example phenyl or p-tolyl, halogens, for examplefluorine, chlorine or bromine, alkoxy and aryloxy, but they preferablycarry no substituents.

[0034] In the groups R¹¹, R¹², R¹³, R¹⁴, R¹⁵, R¹⁶ and R¹⁷, one or morecarbon atoms can independently of one another be replaced withheteroatoms such as nitrogen, oxygen, sulfur or silicon, it beingpossible for the heteroatom(s), independently of one another andindependently of the remaining structure of X, and according to theparticular valency, to carry substituents such as hydrogen, alkylgroups, for example methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl,s-butyl or t-butyl, aryl groups, for example phenyl or p-tolyl,halogens, for example fluorine, chlorine or bromine, alkoxy and aryloxy.Preferably, carbon in the groups R¹¹, R¹², R¹³, R¹⁴, R¹⁵, R¹⁶ and R¹⁷ isnot replaced with heteroatoms.

[0035] A possible meaning of L² is a structure of the formula

[0036] In this formula, Y² is oxygen, sulfur or N—R²⁷, preferablyoxygen.

[0037] Possible groups R²¹, R²², R²³, R²⁴, R²⁵, R²⁶ and R²⁷independently of one another are hydrogen, alkyl, preferably alkylhaving from one to 6 and especially from one to 4 carbon atoms, or arylsuch as phenyl or p-tolyl.

[0038] In one preferred embodiment, the groups R²¹, R²², R²³, R²⁴, R²⁵,R²⁶ and R²⁷ used can independently of one another be a radical selectedfrom the group comprising hydrogen, methyl, ethyl, n-propyl, i-propyl,n-butyl, i-butyl, s-butyl and t-butyl.

[0039] The groups R²¹, R²², R²³, R²⁴, R²⁵, R²⁶ and R²⁷ can independentlyof one another carry substituents such as alkyl groups, for examplemethyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, s-butyl or t-butyl,aryl groups, for example phenyl or p-tolyl, halogens, for examplefluorine, chlorine or bromine, alkoxy and aryloxy, but they preferablycarry no substituents.

[0040] In the groups R²¹, R²², R²³, R²⁴, R²⁵, R²⁶ and R²⁷, one or morecarbon atoms can independently of one another be replaced withheteroatoms such as nitrogen, oxygen, sulfur or silicon, it beingpossible for the heteroatom(s), independently of one another andindependently of the remaining structure of X, and according to theparticular valency, to carry substituents such as hydrogen, alkylgroups, for example methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl,s-butyl or t-butyl, aryl groups, for example phenyl or p-tolyl,halogens, for example fluorine, chlorine or bromine, alkoxy and aryloxy.Preferably, carbon in the groups R²¹, R²², R²³, R²⁴, R²⁵, R²⁶ and R²⁷ isnot replaced with heteroatoms.

[0041] The radicals L¹ and L² can be identical or different, but arepreferably identical.

[0042] A compound of formula (I) can advantageously be prepared byreacting a compound of formula (II):

H₂P—X—PH₂   (II)

[0043] with a compound of formula (IV):

(R¹¹R¹²C)═(C R¹³)—(C═Y¹)—(CR¹⁴)═(CR¹⁵ R¹⁶)   (IV)

[0044] and a compound of formula (V):

(R²¹R²²C)═(C R²³)—(C═Y²)—(C R²⁴)═(C R²⁵R²⁶)   (V)

[0045] R¹¹, R¹², R¹³, R¹⁴, R¹⁵, R¹⁶, R²¹, R²², R²³, R²⁴, R²⁵, R²⁶, Y¹,Y² and X being as defined above.

[0046] Advantageous process conditions which can be used for thepreparation are the process conditions for the preparation of4-phosphorinanones according to Richard P. Welcher and Nancy E. Day, J.Am. Chem. Soc., 27 (1962) 1824-1827.

[0047] Compounds of formula (I), either as individual substances or as amixture, can be used as catalysts or as constituents of systems suitableas catalysts.

[0048] Thus a catalyst containing a compound of formula (I) can be usedin a process for the carbonylation of olefinically unsaturated compounds(X) by reacting a compound of formula (X) with carbon monoxide and acompound (IX) containing a hydroxyl group.

[0049] A system (VI) suitable as a catalyst can advantageously beobtainable by reacting

[0050] a) a source of an ion of a metal (VII) of subgroup VIII of thePeriodic Table of the Elements

[0051] with

[0052] b) a compound of formula (I) as described above.

[0053] Possible metals (VII) are those of subgroup VIII of the PeriodicTable, such as iron, cobalt, nickel, ruthenium, rhodium, palladium,osmium, iridium and platinum, preferably palladium, platinum, rhodiumand iridium and especially palladium, and mixtures thereof.

[0054] Sources of an ion of such a metal which can advantageously beused are salts of such metals, or compounds in which such a metal has aweak coordinate bond, with anions derived from mineral acids such asnitric acid, sulfuric acid or phosphoric acid, carboxylic acids,advantageously C₁-C₁₂ carboxylic acids and preferably acetic acid,propionic acid or butyric acid, sulfonic acids such as methanesulfonicacid, chlorosulfonic acid, fluorosulfonic acid, trifluoromethanesulfonicacid, benzenesulfonic acid, naphthalenesulfonic acid, toluenesulfonicacid, especially p-toluenesulfonic acid, t-butylsulfonic acid or2-hydroxypropanesulfonic acid, sulfonated ion exchangers, halogenatedper acids such as perchloric acid, perfluorinated carboxylic acids suchas trifluoroacetic acid, nonafluorobutanesulfonic acid ortrichloroacetic acid, phosphonic acids such as benzenephosphonic acid,or acids derived from the interaction of Lewis acids with Broenstedacids, anions such as tetraphenylborate and derivatives thereof, ormixtures of said anions.

[0055] It is also possible advantageously to use compounds in which sucha metal is in the zerovalent form with readily cleavable ligands, forexample tris(dibenzylideneacetone)palladium,tetrakis(triphenylphosphine)palladium andbis(tri-o-tolylphosphine)palladium.

[0056] Possible compounds of formula (I) are advantageously those whichexhibit a chelating action when reacting with a metal (VII) or metal ion(VII).

[0057] The molar ratio of compound (I) to metal (VII) can be chosenwithin wide limits. A possible ratio advantageously ranges from 0.5 to50, preferably from 0.5 to 20, particularly preferably from 0.5 to 10and especially from 1 to 5 mol/mol.

[0058] In one preferred embodiment, the catalyst system is obtainable inthe presence of an anion source (IX).

[0059] Anion sources which can be used are compounds already containingthe anion, such as salts, or compounds capable of releasing an anion bya chemical reaction such as heterolytic bond scission.

[0060] Suitable anion sources are disclosed for example in EP-A-495 547.

[0061] Anion sources (IX) which can advantageously be used are compoundscapable of generating an anion by elimination of an H⁺ ion, such asnitric acid, sulfuric acid, phosphoric acid, carboxylic acids,advantageously C₁-C₂₀ carboxylic acids and preferably acetic acid,propionic acid, 2,4,6-trimethylbenzoic acid, 2,6-dichlorobenzoic acid,9-anthracenecarboxylic acid, pivalic acid, 1,2,3-benzenetricarboxylicacid, 1,2,3-benzenetricarboxylic acid 1,3 diesters,2-ethoxy-l-naphthalenecarboxylic acid, 2,6-dimethoxybenzoic acid or5-cyanovaleric acid, sulfonic acids such as methanesulfonic acid,chlorosulfonic acid, fluorosulfonic acid, trifluoromethanesulfonic acid,benzenesulfonic acid, naphthalenesulfonic acid, toluenesulfonic acid,especially p-toluenesulfonic acid, t-butylsulfonic acid or2-hydroxypropanesulfonic acid, sulfonated ion exchangers, halogenatedper acids such as perchloric acid, perfluorinated carboxylic acids suchas trifluoroacetic acid, nonafluorobutanesulfonic acid ortrichloroacetic acid, phosphonic acids such as benzenephosphonic acid,acids derived from the reaction of a Lewis acid such as BF₃, PF₅, AsF₅,SbF₅, TaF₅ or NbF₅ with a Broensted acid such as HF (for examplefluosilicic acid, HBF₄, HPF₆, HSbF₆, tetraphenylboric acid andderivatives thereof), or mixtures of said compounds.

[0062] Preferred compounds (IX) capable of generating an anion byelimination of an H⁺ ion are those with a PK_(a) of at most 3.5 andespecially of at most 2.

[0063] The molar ratio of compound (IX) to metal (VII) is not criticalper se. The molar ratio of compound (IX) to metal (VII) canadvantageously range from 0.5 to 100 and preferably from 1 to 20mol/mol.

[0064] According to the invention, in a process for the carbonylation ofolefinically unsaturated compounds (X) by reacting a compound of formula(X) with carbon monoxide and a compound (XI) containing a hydroxylgroup, in the presence of a catalyst system, it is possible to use acatalyst which contains a system (VI) or, preferably, consists of such asystem.

[0065] In principle, internally and terminally olefinically unsaturatedcompounds can be used, without limitation, as compounds (X). Thecompound (X) can have one or more, such as two or three, units ofolefinic unsaturation, preferably one unit of olefinic unsaturation.

[0066] In one preferred embodiment, the olefinically unsaturatedcompound can advantageously be a substituted or unsubstituted alkene orcycloalkene having preferably from 2 to 30, especially from 2 to 20 andparticularly preferably from 2 to 10 carbon atoms in the molecule. Thealkene or cycloalkene can be substituted for example by one or morehalogen atoms or cyano, ester, carboxyl, amino, amido, nitrile, alkoxy,aryl or thioalkoxy groups. Examples of olefinically unsaturatedcompounds (X) are ethene, propene, 1-butene, 2-butene, isobutene, theisomeric pentenes, hexenes, octenes such as 1-octene,2,4,4-trimethyl-1-pentene and 2,4,4-trimethyl-2-pentene, and dodecenes,1,5-cyclooctadiene, cyclododecene, acrylic acid, methyl acrylate, ethylacrylate, acrylonitrile, acrylamide, an N,N-dialkylacrylamide,acrylaldehyde, methyl methacrylate, the isomeric pentenoic acids, theisomeric methyl pentenoates, the isomeric pentene nitriles, vinylchloride, ethyl vinyl ketone, allyl chloride, methyl allyl ether andstyrene.

[0067] In another preferred embodiment, a possible compound (X) is anoptionally substituted, olefinically unsaturated compound with at leastone terminal olefinic bond, especially an optionally substitutedalpha-olefin. Preferred optionally substituted, olefinically unsaturatedcompounds can be represented by formula (XIII):

H₂C═(C Y³ Y⁴)   (XIII)

[0068] in which Y³ is hydrogen or a hydrocarbyl group and Y⁴ is hydrogenor an electron-withdrawing or electron-donating substituent such ascarboxyl, nitrile, formyl, amino or halogen, or a substituent of theformula Y⁵—R⁴¹, in which Y⁵ is a single bond or the functional group—CO—, —COO—, —OOC—, —NH—, —CONH—, —NHCO—, —O— or —S—, and R⁴¹ is anoptionally substituted alkyl, alkenyl, cycloalkyl, cycloalkenyl, aryl orheterocyclic group. A possible alkyl group is advantageously a C₁- toC₁₀-alkyl group, especially a C₁- to C₆-alkyl group such as methyl,ethyl, n-propyl, i-propyl, n-butyl, i-butyl, s-butyl, t-butyl orn-hexyl. A cycloalkyl group which can advantageously be used is a C₃- toC₆-cycloalkyl group such as cyclopentyl or cyclohexyl. The alkenyl andcycloalkenyl groups can advantageously have the same number of carbonatoms and a carbon-carbon double bond in any position. The aryl groupcan advantageously be a phenyl or naphthyl group. The heterocyclic groupshould preferably have from 3 to 12 atoms, including 1, 2 or 3heteroatoms such as oxygen, sulfur or nitrogen.

[0069] In another preferred embodiment, the compounds (X) used can benucleophiles with a mobile hydrogen, including alkenoic acid derivativessuch as alkenoic acids, alkenoic anhydrides, alkenoic acid amides,alkenoic acid nitriles or alkenoic acid esters. The acid group can belocated directly adjacent to the olefinic double bond, for example itcan be a 2-alkenoic acid derivative. The alkenyl group of the alkenoicacid can be substituted or, preferably, unsubstituted, such as vinyl,1-propenyl, 1-butenyl, 1-pentenyl or 1-hexenyl, and can advantageouslyhave from 2 to 12 carbon atoms. Possible examples are acrylic acid,methacrylic acid, 2-butenoic acid, 2-pentenoic acid, acrylonitrile,methacrylonitrile, 2-butene nitrile, 2-pentene nitrile, acrylamide,methacrylamide, 2-butenamide, 2-pentenamide, an N-substitutedacrylamide, an N-substituted methacrylamide, an N-substituted2-butenamide, an N-substituted 2-pentenamide or an ester of saidalkenoic acids. The N-substituents of the amide group and theO-substituents of the ester group can be aliphatic, cycloaliphatic oraromatic and unsubstituted or substituted, and can preferably have from1 to 10 carbon atoms. Examples of these are methyl acrylate, ethylacrylate, phenyl acrylate, n-propyl acrylate, i-propyl acrylate, n-butylacrylate, i-butyl acrylate, t-butyl acrylate, s-butyl acrylate, thecorresponding methacrylates, 2-butenates, 2-pentenates,N,N-dimethylacrylamide and the corresponding methacrylamides,2-butenamides and 2-pentenamides.

[0070] In another preferred embodiment, as the compound (X), it ispossible to carbonylate an unsubstituted alpha-olefin in the presence ofa nucleophile with a mobile hydrogen to give an ester or other carbonylcompound.

[0071] In another preferred embodiment, a compound (X) which can be usedis n-pentenoic acid or derivatives thereof of formula (XII):

C₄H₇—R³¹   (XII)

[0072] this also being understood in terms of the present invention asmeaning mixtures of such compounds.

[0073] A possible radical R³¹ is —CN or COOR³², it being possible forR³² to be hydrogen, alkyl or aryl, advantageously hydrogen or alkyl,preferably hydrogen, methyl, ethyl, n-propyl, i-propyl, n-butyl,i-butyl, s-butyl or t-butyl, especially hydrogen, methyl or ethyl andparticularly preferably hydrogen or methyl.

[0074] If R³² is an alkyl or aryl group, it can carry substituents suchas functional groups or other alkyl or aryl groups. An alkyl or arylgroup R² preferably carries no substituents.

[0075] In principle, a possible n-pentenoic acid or derivative thereofof formula (XII) is any of the isomers, such as the cis-2, trans-2,cis-3, trans-3 or 4 isomer, or mixtures thereof. Such mixtures cancontain the same radical R³¹ or different radicals R³¹. Preferredmixtures are those containing the same radical R³¹.

[0076] It is advantageous to use cis-2-, trans-2-, cis-3-, trans-3- or4-pentene nitrile or mixtures thereof. Preferred mixtures are thosecontaining at least 80% by weight of 3-pentene nitrile, i.e.cis-3-pentene nitrile and trans-3-pentene nitrile together.

[0077] In another advantageous embodiment, it is possible to use cis-2-,trans-2-, cis-3-, trans-3- or 4-pentenoic acid or mixtures thereof.Preferred mixtures are those containing at least 80% by weight of3-pentenoic acid, i.e. cis-3-pentenoic acid and trans-3-pentenoic acidtogether.

[0078] In another advantageous embodiment, it is possible to use methylcis-2-, trans-2-, cis-3-, trans-3- or 4-pentenoate or mixtures thereof.Preferred mixtures are those containing at least 80% by weight of methyl3-pentenoate, i.e. methyl cis-3-pentenoate and methyl trans-3-pentenoatetogether.

[0079] Pentenoic acid and derivatives thereof of formula (XII) can beobtained by processes known per se, for example by the addition ofcarbon monoxide and a compound containing a hydroxyl group, or theaddition of hydrogen cyanide, onto butadiene in the presence of acatalyst.

[0080] The molar ratio of metal (VII) to compound (X) is not criticalper se. A molar ratio of metal (VII) to compound (X) ranging from 10⁻⁷:1to 10⁻¹:1, preferably from 10⁻⁶:1 to 10⁻²:1 has proved advantageous.

[0081] According to the invention, the compound of formula (X) isreacted with carbon monoxide. The carbon monoxide can be used as thepure compound or in the presence of gases which substantially do notadversely affect the process according to the invention, especiallygases with an inert behavior. Examples of possible inert gases arenitrogen, hydrogen, carbon dioxide, methane and the noble gases such asargon.

[0082] Advantageously, the molar ratio of compound (X) to carbonmonoxide can be at least 1:1, preferably at least 3:1, especially atleast 5:1, preferably in the range from 5:1 to 50:1 and particularlypreferably in the range from 7:1 to 15:1. If the process according tothe invention is carried out with molar ratios of compound (I) to carbonmonoxide of less than 5:1, especially of less than 3:1 and particularlyof less than 1:1, this can result in a rapid impairment of theproperties of the catalyst system.

[0083] According to the invention, the compound of formula (X) isreacted with a compound (XI) containing a hydroxyl group. Compounds (XI)are understood in terms of the present invention as meaning individualcompounds (XI) as well as mixtures of different compounds of this type.

[0084] The type of compound (XI) at least partially determines the endproduct of the present process. If water is used as the compound (XI),the corresponding acid is obtained, whereas if an alcohol such as analkanol is used, the corresponding ester is obtained. Possible alcoholsare primary, secondary or tertiary alcohols, preferably primaryalcohols, and advantageously C₁-C₃₀ alkanols which can optionally carrysubstituents such as one or more halogen, nitrile, carbonyl, alkoxy oraryl groups. Possible alkanols are advantageously methanol, ethanol,n-propanol, i-propanol, n-butanol, i-butanol, s-butanol, t-butanol,n-hexanol, n-octanol, i-octanol, 2-ethylhexanol, cyclohexanol, benzylalcohol, phenylethyl alcohol, ethylene glycol, 1,2-propanediol,1,3-propanediol, neopentyl glycol, trimethylolpropane orpentaerythritol, preferably methanol, ethanol, n-propanol, i-propanol,n-butanol, i-butanol, s-butanol or t-butanol, particularly preferablymethanol or ethanol and especially methanol.

[0085] The molar ratio of compound (X) to compound (XI) is not criticalper se and can vary within wide limits, advantageously ranging from0.001:1 to 100:1 mol/mol.

[0086] The catalyst system can be prepared before being used in theprocess according to the invention or during the actual processaccording to the invention.

[0087] If the catalyst system is prepared during the actual processaccording to the invention, it has proved advantageous to use metalcompounds (III) which are soluble in the reaction mixture to the extentthat they can form an active catalyst system with the other components.

[0088] The catalyst system employed in the process according to theinvention can be used in the heterogeneous or, preferably, homogeneousphase.

[0089] The catalyst system can advantageously be obtained in the liquidphase. The liquid phase can be formed of one or more of the componentsfrom which the catalyst system is obtainable or has been obtained.Another possibility is to prepare the liquid phase using an inorganicor, preferably, organic liquid diluent.

[0090] Possible liquid diluents are advantageously aprotic liquiddiluents such as ethers, for example diethyl ether, dimethyl ether,ethylene glycol dimethyl ether, diethylene glycol dimethyl ether,tetrahydrofuran, polyethers, functionalized polyethers, anisole,2,5,8-trioxanonane, diisopropyl ether and diphenyl ether, aromatics,including halogenated aromatics, for example benzene, toluene, o-xylene,m-xylene, p-xylene, chlorobenzene, o-dichlorobenzene, m-dichlorobenzeneand p-dichlorobenzene, alkanes, including halogenated alkanes, forexample hexane, heptane, 2,2,3-trimethylpentane, methylene dichlorideand carbon tetrachloride, nitriles, for example benzonitrile andacetonitrile, esters, for example methyl benzoate, methyl acetate,dimethyl phthalate and butyrolactone, sulfones, for example diethylsulfone, diisopropyl sulfone, tetrahydrothiophene 1,1-dioxide(“sulfolan”), 2-methylsulfolan, 3-methylsulfolan and2-methyl-4-butylsulfolan, sulfoxides, for example dimethyl sulfoxide,amides, including halogenated amides, for example dimethylformamide,dimethylacetamide and N-methylpyrrolidone, ketones, for example acetone,methyl ethyl ketone and methyl isobutyl ketone, and mixtures thereof.

[0091] Particularly preferred liquid diluents are those whose boilingpoint is higher than that of the particular product obtained by theprocess according to the invention. This can facilitate the separationof the product from the remaining reaction mixture, for example bydistillation.

[0092] The process according to the invention can advantageously becarried out at a temperature ranging from 20 to 250° C., preferably from40 to 200° C., particularly preferably from 70 to 170° C. and especiallyfrom 80 to 140° C.

[0093] The process according to the invention can advantageously becarried out under a total pressure of 1*10⁵ to 200*10⁵ Pa, preferably of5*10⁵ to 70*10⁵ Pa and especially of 6*10⁵ to 20*10⁵ Pa.

[0094] The process according to the invention can be carried outcontinuously, batchwise or semicontinuously.

[0095] The product of the process can be separated from the othercomponents by methods known per se, such as extraction or distillation.

[0096] By virtue of the high n/i ratio in the process according to theinvention, the subsequent purification cost can be markedly reduced asfewer unwanted by-products are obtained.

[0097] Another advantage of the process according to the invention isthat the remaining components containing the catalyst system can berecycled into the process according to the invention, it being possiblefor fresh catalyst to be added if desired.

EXAMPLES

[0098] Preparation of Compounds of Formula (I)

Example 1

[0099] 14.6 g (0.106 mol) of 2,6-dimethyl-2,5-heptadien-4-one(“phorone”) and 5.0 g (0.053 mol) of 1,2-bisphosphinoethane were broughttogether in a Schlenk tube and stirred for 20 hours at 120° C. The lightyellow solid formed was washed with 2×20 ml of pentane and then driedunder reduced pressure to give a white powder. The product wascharacterized by means of ³¹P NMR spectroscopy, elemental analysis andGC/MS.

[0100] Yield: 18.2 g, corresponding to 93% of theory

Example 2

[0101] The procedure of Example 1 was followed except that the1,2-bisphosphinoethane was replaced with 5.7 g (0.053 mol) of1,3-bisphosphinopropane.

[0102] Yield: 18.7 g, corresponding to 92% of theory

Example 3

[0103] The procedure of Example 1 was followed except that the1,2-bisphosphinoethane was replaced with 6.5 g (0.053 mol) of1,3-bisphosphinopropane.

[0104] Yield: 19.9 g, corresponding to 94% of theory

Example 4

[0105] The procedure of Example 1 was followed except that the1,2-bisphosphinoethane was replaced with 7.5 g (0.053 mol) of1,2-bisphosphinobenzene.

[0106] Yield: 19.9 g, corresponding to 86% of theory

Example 5

[0107] The procedure of Example 1 was followed except that 2 g (0.021mol) of 1,2-bisphosphinoethane and 10 g (0.0427 mol) ofdibenzylideneacetone were used.

[0108] Yield: 11.0 g, corresponding to 92% of theory

Example 6

[0109] The procedure of Example 5 was followed except that the1,2-bisphosphinoethane was replaced with 2.3 g (0.021 mol) of1,3-bisphosphinopropane.

[0110] Yield: 11.1 g, corresponding to 90% of theory

[0111] Preparation of Systems of Formula (VI)

Example 7

[0112] 8.5 g (0.023 mol) of 1,2-bis(4-phosphorinone)ethane of Example 1were dissolved in 50 ml of acetone and the solution was slowly addeddropwise to a solution of palladium diacetate in 50 ml of acetone. Theyellow solid which immediately precipitated out was separated off bymeans of a frit, washed with 2×20 ml of toluene and dried under reducedpressure.

[0113] Yield: 13.2 g, corresponding to 96% of theory

Example 8

[0114] The procedure of Example 7 was followed except that the1,2-bis(4-phosphorinone)ethane was replaced with 8.8 g (0.023 mol) of1,2-bis(4-phosphorinone)propane of Example 2.

[0115] Yield: 13.5 g, corresponding to 96% of theory

Example 9

[0116] The procedure of Example 7 was followed except that the1,2-bis(4-phosphorinone)ethane was replaced with 9.2 g (0.023 mol) of1,2-bis(4-phosphorinone)butane of Example 3.

[0117] Yield: 13.8 g, corresponding to 96% of theory

[0118] Carbonylation of Ethene

Example 10

[0119] 28 mg (0.12 mmol) of palladium diacetate, 81 mg (0.22 mmol) of1,2-bis(4-phosphorinone)ethane of Example 1, 94 mg (0.5 mmol) ofp-toluenesulfonic acid and 150 ml of n-butanol were placed in a 400 mlglass autoclave with a gas dispersion stirrer. After sealing, a carbonmonoxide pressure of 4 bar (4*10⁵ Pa) was applied. The autoclave washeated to 90° C. and the total pressure was adjusted to 7 bar (7*10⁵ Pa)for a molar ratio of carbon monoxide to ethene of 1:1. After one hourthe autoclave was cooled, the pressure was released and the liquiddischarge was examined by gas chromatography. No deposition of palladiumwas observed.

[0120] The results are collated in Table 1.

Example 11

[0121] 28 mg (0.12 mmol) of palladium diacetate, 81 mg (0.22 mmol) of1,2-bis(4-phosphorinone)ethane of Example 1, 60 mg (0.6 mmol) ofmethanesulfonic acid and 150 ml of n-butanol were placed in a 400 mlglass autoclave with a gas dispersion stirrer. After sealing, a carbonmonoxide pressure of 4 bar (4*10⁵ Pa) was applied. The autoclave washeated to 90° C. and the total pressure was adjusted to 7 bar (7*10⁵ Pa)for a molar ratio of carbon monoxide to ethene of 1:1. After one hourthe autoclave was cooled, the pressure was released and the liquiddischarge was examined by gas chromatography. No deposition of palladiumwas observed.

[0122] The results are collated in Table 1.

Example 12

[0123] 28 mg (0.12 mmol) of palladium diacetate, 81 mg (0.22 mmol) of1,2-bis(4-phosphorinone)ethane of Example 1, 410 mg (23 mmol) of waterand 150 ml of n-butanol were placed in a 400 ml glass autoclave with agas dispersion stirrer. After sealing, a carbon monoxide pressure of 4bar (4*10⁵ Pa) was applied. The autoclave was heated to 140° C. and thetotal pressure was adjusted to 7 bar (7*10⁵ Pa) for a molar ratio ofcarbon monoxide to ethene of 1:1. After one hour the autoclave wascooled, the pressure was released and the liquid discharge was examinedby gas chromatography. No deposition of palladium was observed.

[0124] The results are collated in Table 1.

Example 13

[0125] 28 mg (0.12 mmol) of palladium diacetate, 81 mg (0.22 mmol) of1,2-bis(4-phosphorinone)ethane of Example 1, 245 mg (0.1 mmol) of9-anthracenecarboxylic acid and 150 ml of n-butanol were placed in a 400ml glass autoclave with a gas dispersion stirrer. After sealing, acarbon monoxide pressure of 4 bar (4*10⁵ Pa) was applied. The autoclavewas heated to 140° C. and the total pressure was adjusted to 7 bar(7*10⁵ Pa) for a molar ratio of carbon monoxide to ethene of 1:1. Afterone hour the autoclave was cooled, the pressure was released and theliquid discharge was examined by gas chromatography. No deposition ofpalladium was observed.

[0126] The results are collated in Table 1.

Example 14

[0127] 36 mg (0.06 mmol) of the system of Example 7, 30 mg (0.3 mmol) ofmethanesulfonic acid and 150 ml of n-butanol were placed in a 400 mlglass autoclave with a gas dispersion stirrer. After sealing, a carbonmonoxide pressure of 4 bar (4*10⁵ Pa) was applied. The autoclave washeated to 90° C. and the total pressure was adjusted to 7 bar (7*10⁵ Pa)for a molar ratio of carbon monoxide to ethene of 1:1. After one hourthe autoclave was cooled, the pressure was released and the liquiddischarge was examined by gas chromatography. No deposition of palladiumwas observed.

[0128] The results are collated in Table 1. TABLE 1 Conversion of TOFSelectivity in respect of Example n-butanol [%] [h⁻¹] propionic acidester [%] 10 80 10950 >99 11 95 12900 >99 12 50 6840 >99 13 45 6150 >9914 98 26700 >99

Example 15

[0129] 70 mg (0.31 mmol) of palladium diacetate, 230 mg (0.62 mmol) of1,2-bis(4-phosphorinone)ethane of Example 1, 590 mg (3.1 mmol) ofp-toluenesulfonic acid, 80 ml (830 mmol) of 3-pentene nitrile and 34 mlof methanol were placed in a 400 ml glass autoclave with a gasdispersion stirrer. After sealing, a carbon monoxide pressure of 4 bar(4*10⁵ Pa) was applied. The autoclave was heated to 90° C. and the totalpressure was adjusted to 7 bar (7*10⁵ Pa). After one hour the autoclavewas cooled, the pressure was released and the liquid discharge wasexamined by gas chromatography. No deposition of palladium was observed.

[0130] The results are collated in Table 2.

Example 16

[0131] 70 mg (0.31 mmol) of palladium diacetate, 240 mg (0.62 mmol) of1,3-bis(4-phosphorinone)propane of Example 2, 590 mg (3.1 mmol) ofp-toluenesulfonic acid, 80 ml (830 mmol) of 3-pentene nitrile and 34 mlof methanol were placed in a 400 ml glass autoclave with a gasdispersion stirrer. After sealing, a carbon monoxide pressure of 4 bar(4*10⁵ Pa) was applied. The autoclave was heated to 90° C. and the totalpressure was adjusted to 7 bar (7*10⁵ Pa). After one hour the autoclavewas cooled, the pressure was released and the liquid discharge wasexamined by gas chromatography. No deposition of palladium was observed.

[0132] The results are collated in Table 2.

Example 17

[0133] 123 mg (0.2 mmol) of system (VI) of Example 8, 380 mg (2.0 mmol)of p-toluenesulfonic acid, 80 ml (830 mmol) of 3-pentene nitrile and 34ml of methanol were placed in a 400 ml glass autoclave with a gasdispersion stirrer. After sealing, a carbon monoxide pressure of 4 bar(4*10⁵ Pa) was applied. The autoclave was heated to 90° C. and the totalpressure was adjusted to 7 bar (7*10⁵ Pa). After one hour the autoclavewas cooled, the pressure was released and the liquid discharge wasexamined by gas chromatography. No deposition of palladium was observed.

[0134] The results are collated in Table 2. TABLE 2 SelectivityConversion of TOF Carbonylation in respect of Ex. 3-PN [%] [h⁻¹]selectivity [%] n [%] 15 70 1705 91 80.5 16 94 2500 >99 97.2 17 953900 >99 98.3

Example 18

[0135] 70 mg (0.31 mmol) of palladium diacetate, 230 mg (0.62 mmol) of1,2-bis(4-phosphorinone)ethane of Example 1, 590 mg (3.1 mmol) ofp-toluenesulfonic acid, 102 ml (840 mmol) of methyl 3-pentenoate and 34ml of methanol were placed in a 400 ml glass autoclave with a gasdispersion stirrer. After sealing, a carbon monoxide pressure of 4 bar(4*10⁵ Pa) was applied. The autoclave was heated to 90° C. and the totalpressure was adjusted to 7 bar (7*10⁵ Pa). After one hour the autoclavewas cooled, the pressure was released and the liquid discharge wasexamined by gas chromatography. No deposition of palladium was observed.

[0136] The results are collated in Table 3.

Example 19

[0137] 70 mg (0.31 mmol) of palladium diacetate, 240 mg (0.62 mmol) of1,3-bis(4-phosphorinone)propane of Example 2, 590 mg (3.1 mmol) ofp-toluenesulfonic acid, 102 ml (840 mmol) of methyl 3-pentenoate and 34ml of methanol were placed in a 400 ml glass autoclave with a gasdispersion stirrer. After sealing, a carbon monoxide pressure of 4 bar(4*10⁵ Pa) was applied. The autoclave was heated to 90° C. and the totalpressure was adjusted to 7 bar (7*10⁵ Pa). After one hour the autoclavewas cooled, the pressure was released and the liquid discharge wasexamined by gas chromatography. No deposition of palladium was observed.

[0138] The results are collated in Table 3.

Example 20

[0139] 123 mg (0.2 mmol) of system (VI) of Example 8, 380 mg (2.0 mmol)of p-toluenesulfonic acid, 102 ml (840 mmol) of methyl 3-pentenoate and34 ml of methanol were placed in a 400 ml glass autoclave with a gasdispersion stirrer. After sealing, a carbon monoxide pressure of 4 bar(4*10⁵ Pa) was applied. The autoclave was heated to 90° C. and the totalpressure was adjusted to 7 bar (7*10⁵ Pa). After one hour the autoclavewas cooled, the pressure was released and the liquid discharge wasexamined by gas chromatography. No deposition of palladium was observed.

[0140] The results are collated in Table 3. TABLE 3 SelectivityConversion of M TOF Carbonylation in respect Ex. 3-P [%] [h⁻¹]selectivity [%] of n [%] 18 71 1770 92 80.6 19 95 2550 >99 97.5 20 963990 >99 98.4

We claim:—
 1. A compound of formula (I) suitable as a catalyst or forthe preparation of a catalyst system: L¹-X-L²   (I) in which X is alower alkylene group, an arylene group or an alkarylene group; L¹ is

in which Y¹ is oxygen, sulfur or N—R¹⁷, R¹², R¹⁴, R¹⁵, R¹⁶ and R¹⁷independent of one another being hydrogen, alkyl or aryl; and R¹¹ andR¹³ independently of one another being alkyl or ayrl, L² is

in which Y² is oxygen, sulfur or N—R²⁷, R²², R²⁴, R²⁵, R²⁶ and R²⁷independently of one another being hydrogen, alkyl or aryl, R²¹ and R²³independently of one another being alkyl or aryl, it being possible forL¹ and L² to be identical or different.
 2. A compound of formula (I) asclaimed in claim 1 in which L¹ and L² are identical.
 3. A compound offormula (I) as claimed in claim 1 or 2 in which X is a lower alkylenegroup.
 4. A compound of formula (I) as claimed in any of claims 1 to 3in which X is selected from the group comprising methylene,1,2-ethylene, 1,3-propylene and 1,4-butylene.
 5. A compound of formula(I) as claimed in any of claims 1 to 4 in which Y¹ and Y² are oxygen. 6.A compound of formula (I) as claimed in any of claims 1 to 5 in whichR¹¹, R¹², R¹³, R¹⁴, R¹⁵, R¹⁶, R¹⁷, R²¹, R²², R²³, R²⁴, R²⁵, R²⁶ and R²⁷,within the definitions as claimed in claim 1, independently of oneanother are selected from the group comprising hydrogen, methyl, ethyl,n-propyl, i-propyl, n-butyl, i-butyl, s-butyl and t-butyl.
 7. A processfor the preparation of a compound of formula (I) as claimed in any ofclaims 1 to 6, wherein a compound of formula (II): H₂P—X—PH₂   (II) isreacted with a compound of formula (IV): (R¹¹ R¹²C)═(CR¹³)—(C═Y¹)—(CR¹⁴)═(CR¹⁵R¹⁶)   (IV) and a compound of formula (V): (R²¹R²²C)═(C R²³)—(C═Y²)—(C R²⁴)═(C R²⁵R²⁶)   (V) R¹¹, R¹², R¹³, R¹⁴, R¹⁵,R¹⁶, R²¹, R²², R²³, R²⁴, R²⁵, R²⁶, Y¹, Y² and X being as defined in anyof claims 1 to
 6. 8. The use of a compound of formula (I) as claimed inany of claims 1 to 6 as a catalyst or as a constituent of a systemsuitable as a catalyst.
 9. A system (VI) suitable as a catalyst,obtainable by reacting a) a source of an ion of a metal (VII) ofsubgroup VIII of the Periodic Table of the Elements with b) a compoundof formula (I) as claimed in any of claims 1 to
 6. 10. A system (VI) asclaimed in claim 9 in which the metal (VII) is selected from the groupcomprising palladium, platinum, rhodium and iridium.
 11. A system (VI)as claimed in claim 9 or 10 in which the metal (VII) used is palladium.12. A system (VI) as claimed in any of claims 9 to 11 obtainable in thepresence of an anion source (IX).
 13. A system (VI) as claimed in claim13 in which the anion source (IX) used is a compound capable ofgenerating an anion by elimination of an H⁺ ion.
 14. A process for thecarbonylation of olefinically unsaturated compounds (X) by reacting acompound of formula (X) with carbon monoxide and a compound (XI)containing a hydroxyl group, in the presence of a catalyst, wherein thecatalyst contains a compound of formula (I) as claimed in any of claims1 to
 6. 15. A process for the carbonylation of olefinically unsaturatedcompounds (X) by reacting a compound of formula (X) with carbon monoxideand a compound (XI) containing a hydroxyl group, in the presence of acatalyst system, wherein the catalyst contains a system of formula (VI)as claimed in any of claims 8 to
 14. 16. A process as claimed in claim15 or 16 in which the compound of formula (X) used is n-pentenoic acidor derivatives thereof of formula (XII): C₄H₇—R³¹   (XII) in which R³¹is —CN or COOR³², where R³² is hydrogen, alkyl or aryl.
 17. A process asclaimed in claim 17 in which R³² is selected from the group comprisinghydrogen, methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, s-butyland t-butyl.
 18. A process as claimed in any of claims 15 to 18 in whichat least 80% by weight of the compound of formula (XII) used is3-pentene nitrile.
 19. A process as claimed in any of claims 15 to 18 inwhich at least 80% by weight of the compound of formula (XII) used ismethyl 3-pentenoate. Compound suitable as a catalyst or for thepreparation of a catalyst system 5 Abstract A compound of formula (I)suitable as a catalyst or for the preparation of a catalyst system:L¹-X-L²   (I) is provided, in which X is a lower alkylene group, anarylene group or an alkarylene group; L¹ is

in which Y¹ is oxygen, sulfur or N—R¹⁷, R¹¹, R¹², R¹³, R¹⁴, R¹⁵, R¹⁶ andR¹⁷ independently of one another being hydrogen, alkyl or aryl; and L²is

in which Y² is oxygen, sulfur or N—R²⁷, R²¹, R²², R²³, R²⁴, R²⁵, R²⁶ andR²⁷ independently of one another being hydrogen, alkyl or aryl, it beingpossible for L¹ and L² to be identical or different.